Monocarboxylic acid esters and their production



Patented May 19, 1936 UNITED STATES MONOCARBOXYLIC ACID ESTERS AND THEIRPRODUCTION Harold S. Holt, Wilmington, Del., assignor to E. I. du Pontde Nemours & Company, Wilmington, Del., a corporation of Delaware NoDrawing. Application September 28, 1934,

Serial No. 745,848

13 Claims. (Cl. 260-1661 This invention relates to new compositions ofmatter, more particularly to monocarboxylic acid esters of abietylalcohol, to their method of prepparation, and to their use in plasticand coating 5 compositions.

This invention has as an object the provision of processes for thepreparation of monocarboxylic acid esters of abietyl alcohol. A furtherobject is the preparation of plastic and coating compositions containingsuch esters. A fur ther object is-the class of esters thus prepared andused. Other objects will appear hereinafter.

These objects are accomplished by the following invention wherein amonocarboxylic acid ester of abietyl alcohol is prepared and thenformulated into plastic and coating compositions,

Monocarboxylic acid esters of abietyl alcohol may be prepared byreacting the monocarboxylic acid with the abietyl alcohol at atemperature sufficiently high to expel the water produced in thereaction as it is formed, or by using a catalyst with or without asolvent to aid in the removal of the water. The esters may also beprepared from the alcohol and the anhydride or acid halide of themonocarboxylic acid. A further method of preparation lies in esterinterchange of the abietyl'alcohol with an ester of the monocarboxylicacid with an alcohol more volatile than the abietyl alcohol. A stillfurther method of preparation is by the reaction of the sodium or othermetal salt of the monocarboxylic acid with the esters 'of abietylalcohol with inorganic acids such as the hydrogen halides.

The abietyl alcohol employed in this invention is conveniently preparedby the hydrogenation, in the presence of suitable catalysts such ascopper chromite, of ,abietic acid, its esters, salts, or anhydride,according to the general method described in copending application of W.A. Lazier (Serial No. 584,573, filed January 2, 1932) for carboxylichydrogenation of alicyclic acids. Crude abietyl alcohol as obtained by asimilar hydrogenation of ordinary rosin may also be used. The inventionis not however limited to esters oi. abietyl alcohol obtained in thisway. This alcohol, for example, may also be obtained by the sodiumreduction of abietic acid esters according to the well-known generalmethod of Bouveault and Blane.

Having outlined above the general principles and processes of theinvention, the following examples are added for purposes of illustrationbut not in limitation:

Example 1.Abz'etyl methacrylate A solution of 144 g. of abietyl alcohol(0.5 mol.) in 200 g. of chloroform was prepared, and placed in a flaskfitted with a reflux condenser having 5 the end closed with a dryingtube. To this solution was added g. of methacrylyl chloride (0.625 mol.)over a period of 5 minutes, heated on a water-bath for one and one-halfhours, cooled, diluted with chloroform, Washed. with 200 cc. of 5%sodium hydroxide solution, and then washed three times with water using500 cc. portions each time. The washed chloroform solution was driedover calcium chloride, filtered, and the filtrate vacuum distilled atroom temperature, using a slow stream of carbon dioxide to sweep out thevolatile material. The product obtained was a yellow, viscous liquidhaving a slight odor of abietyl alcohol.

Example 2.Abiet1/l ester of China-wood oil acids To 14 g. of China-woodoil acids (0.05 mol.)

were added 13.4 g. of abietyl alcohol (0.05 mol.).

and the mixture heated in an open vessel at 225 C. for one hour. Theproduct obtained was a viscous oil of acid number 33.6.

The above ester used directly as a varnish was completely resistant tofrosting (gas oven test) and showed drying properties comparable tothose of a twenty-five gallon rosin-China-wood oil varnish.

Example 3.--Ab'ietyl acetate A mixture of 57.6 g. of abietyl alcohol(0.2 mol.) and 51 g. of acetic anhydride (0.5 mol.) was re- 35 fluxedfor two hours, after which time the product was vacuum distilled and thefraction boiling between 180 C. and 210 C. at 3 mm. pressure collected.The ester thus obtained was a light yellow, viscous oil, having asaponification number of 157.

Example 4.Abz'etyl isobutyrate A mixture of 57.6 g. of abietyl alcohol(0.2 mol.) and 59 g. of isobutyric anhydride (0.37 mol.) was refluxedfor two hours, after which time the isobutyric acid formed in thereaction and the excess isobutyric anhydride was distilled ofi, theresidue fractionated, and the fraction boiling between and 205 C. at 3mm. pressure collected. The ester thus formed was a light yellow,viscous oil having a saponiflcation number of 142.5.

Example 5.Abietyl stearate A mixture of 557.6 g. of abietyl alcohol (0.2mol.). 5

litharge, and 400 g. of toluol was heated to boiling in an apparatusdesigned to separate the methanol produced in the reaction and returnthe toluol to the reaction vessel. When the theoretical amount ofmethanol had been collected, the solution was filtered, and the toluolremoved by vacuum distillation. The ester obtained was a light yellow,viscous oil.

' Example 6.-.-Abietyl hydromystearate' A mixture of 25 g. of abietylalcohol (0.09 mol.), 25 g. of the sapon'ification product ofhydrogenated castor oil (which is mainly hydroxystearic acid), and 5drops of concentrated sulfuric acid were heated at to C. for three hoursat 10 to 20 mm. pressure, throughout which period of heating thereaction .vessel was swept with a slow currentpf nitrogen. The reactionmass 'was then washed three times in boiling .water, and the productdried. The ester thus obtained was light yellow, viscous oil having anacid number of 6.

The esters of the present invention may be made by widely differentmethods and the methods above described are susceptible of considerablemodification. Catalysts other than ptoluenesulfonic acid may be usedsuch as sulfuric acid, hydrochloric acid benzenesulfonic acid, and thelike. ,Toluene may be replaced by other inert solvents such as ethylenedichloride, xylene,

carbon tetrachloride, benzene, and the like.

Although the use of solvents and catalysts is in general preferred,either may be used without the other. The temperature of the reactionmay be varied, depending upon the process employed, on the ester and onthe nature of the carboxylic acid employed.

Monocarboxylic acids in general may be used including acrylic acid,methacrylic acid, crotonic acid, levulinic acid, oleic acid, ricinoleicacid,

acids obtainable from the saponification of drying, semi-drying, andnon-drying oils, lactic acid, naphthenic acids, glycollic acid, butyricand isobutyric acids, hydroxycaproic acids, capric acid, chloroaceticacid, hexahydrobenzoic acid, acids obtained from the oxidation of waxes,abietic acid, palmitic acid, phenylacetic acid, benzoic acid, toluicacids, salicylic acid, cinnamic acid, phenylglycollic acid, quinic acid,benzoylactic acid, and the like.

The monocarboxylic acid esters of abietyl alcohol of the presentinvention such as those above described are soluble in organic solventsand either alone or in combination with drying oils, cellulosederivatives, polyhydric alcoholpolycarboxylic acid resins and othersynthetic resins may be used as coating and impregnating compositions.The esters may be blended by heating, by mutual solvents, or by othermeans with oils including drying, semi-drying, and nondrying oils,cellulose derivatives; natural synthetic resins. e. g., ,rosin, kauri,vinyl resins, cournarone-indene resins, ureaaldehyde' resins,phenol-aldehyde resins, polyhydric alcohol-polycarboxylic acid resins,acrylic and methacrylic acid ester polymers, natural and syntheticwaxes,

e. g., Montan wax, beeswax, 'candelilla wax,

dodecyl stearate, etc. The usual pigments, dyes, fillers, solvents, asneeded and desired, may be added to compositions comprising the abietylesters of the present invention.

These new esters, either alone or combined with one or more of the abovesubstances, find useful application as impregnating and coating agentsfor paper, cloth, wood, porous stone, regenerated cellulose, rubberizedfabrics, etc.; as sandwiching materials or adhesives therefor in themanufacture of shatter-proof glass; as linoleum plastics in themanufacture of floor coverings; as adhesives, cements and sealing waxesfor general use; and as binding agents for mica, asbestos and the likein the manufacture of insulating materials and for cotton flock in themanufacture of artificial suede, etc.

Some of the esters of the present invention,

particularly those of unsaturated acids, are of.

great; utility. Thus, the China-wood oil acid ester is unique in beingpractically resistant to frosting, as shownin the gas oven test, and inhaving drying properties comparable to those of a 25 gallonrosin-China-wood oil varnish. The

abietyl ester of methacrylic acid dries slowly to a hard, clear film.Abietyl abietate is an excellent varnish gum.

The invention is also applicable to the preparation of monocarboxylicacid esters of alcohols obtained through the carboxylic reduction(catalytic or otherwise) of natural acidic resins generally, e. g.,kauri,'Manila, Congo, sandaric, da-

obtainable by the substantially solely carboxylic hydrogenation ofrosin.

3. A monocarboxylic acid ester of abietyl alcohol.

4. An ester of abietyl alcohol with an unsaturated monocarboxylic acid.g

5. An ester of abietyl alcohol with an open chain unsaturatedmonocarboxylic acid.

6. Abietyl' methacrylate.

'7. Process for the preparation of monocarboxylic acid esters, whichcomprises heating an alcohol obtainable by the substantially solelycarboxylic reduction of a natural acidic resin with v a member of theclass consisting of monocarboxylic acids, their anhydrides, acidhalides, and

esters with volatile alcohols.

8. Process for the preparation of esters, which comprises heatingabietyl alcohol with a monocarboxylic acid.

9. Process of claim 8, wherein an inert solvent is used to assist theesterification.

10. Process of claim 8, wherein a catalyst is used to assisttheesterification.

11. Process for the production of monocarboxylic acidesters, whichcomprises heating abietyl alcohol with monocarboxylic,,acid in thepresence of an inert solvent and a catalyst.

12. Abietyl levulinate. 13. Abietyl acetate.

HAROLD S. HOLT.

CERTIFICATE QF CORRECTION'.

May 19, 1936,

' Patent No 2,040,849.

(Seal) HAROLD s. HOL' It is hereby certified thaterror appears in theprinted specification of the above numbered patent requiring correctionas follows: Page 2', first 4 column, line 63, after the word "natural"insert and; and that the said Letters Patent should be' read with thiscorrecton therein that the same may conform to the record. of the casein the Patent Office.

Signed and se'alzed this 15th day of September, A. D, 1936.

HeriryYan Ara'dale v Acting Commissioner of Patents-

